Nationally, 9.4 million youth 17 years and under attend YMCA programs. Thus, the YMCA is uniquely position to influence childhood obesity levels by increasing physical activity levels and promoting dietary changes. In many communities, particularly those that are low income, rural, and/or unsafe, the YMCA's out-of-school time (OST) programs (afterschool - 3-6pm and all day summer programs) represent one of the few outside-of- school settings where youth can be physically active and receive nutritious food options (e.g., fruits and vegetables). Our ongoing collaborative work with the YMCA has indicated that youth attending YMCA OST programs have low levels of moderate-to-vigorous physical activity and are provided snacks of low-nutrient energy dense choices (e.g., pretzels, chips, granola bars). Currently, the YMCA has no national policies or benchmarks related to promoting physical activity or the quality of snacks during its afterschool or summer programs. Our collaborative team includes the CEO and Directors of the three Columbia, SC YMCAs, community stakeholders, and university researchers. Using community-based participatory research principles and drawing from the unique experiences, capabilities, and diversity of our collaborative team, the following question and specific aims were developed to address the critical core issues of childhood obesity: What policies can be developed and effectively implemented to ensure that the YMCA OST programs contribute to youth meeting recommendations for physical activity and dietary intake? Specifically, this proposal will seek to: 1) collaboratively develop policies and benchmarks designed to promote physical activity and improve nutrition during YMCA summer and afterschool programs; 2) implement and evaluate these policies and benchmarks using a non-randomized pre/post-test comparison group design with approximately 780 youth (5- 12yrs old, 50% girls, 50% African American); and 3) describe organizational and staff changes in attitudes and beliefs towards promoting physical activity and good dietary behaviors before and after policy implementation. The proposed research will inform policy development for YMCA youth-oriented programs in the greater Columbia, SC area. Importantly, given that almost 10 million youth attend YMCAs nationally, this research has the potential to reduce childhood obesity through ensuring that youth who attend YMCA programs engage in sufficient amounts of health-enhancing physical activity and consume foods high in dietary quality. The information gained in this study will lay the groundwork for evaluating policy uptake and implementation in subsequent studies in a nationally-representative sample of YMCA summer and afterschool programs.